Answer:
7a-3b
Step-by-step explanation:
(10a-7b) - (3a-4b)
Subtract like terms:
10a-3a = 7a
-7a--4b = -3b
Put together:
7a - 3b
10a-7b - (3a-4b) = 10a - 7b - 3a + 4b
= 10a - 3a - 7b + 4b
= 7a - 3b